The invention relates to a process for controlling a welding device and to a welding means.
In electrical spot and resistance welding it is often difficult to maintain the required quality scale for the welding spots.
It has been shown that the quality, especially the load capacity of a finished welding spot, depends on a plurality of factors, among others, on the electrode force, i.e. on the force with which the electrodes lie pressed against the material to be welded during the welding process, on the size of the welding current, and also on the state of the electrodes or pole caps. The latter, during welding, are subject to heavy wear and change of their surfaces, for example, in the form of a flattening due to wear, but also metallurgically, by the material of the electrodes or pole caps changing on the surface, as is the case in welding of galvanized sheets with copper electrodes. This leads to changes in the thermal and electrical properties of the electrodes or pole caps, conventionally used to execute a plurality of welding spots in time succession.
The object of the invention is to devise a process and welding means ensuring flawless welding spots, in spite of inevitable changes which occur mechanically, metallurgically, etc. on the electrodes or their surfaces by use and hereinafter are generally called "ageing".